Well either that one guy has managed to cause a story to spread around the boxing world in a matter of a few hours, or there are other primary sources. From what I gather from reading your link, that charles_nzo guy is behind the AlexAriza fake account, he is claiming Saj sent him a message assuming it to be the real AlexAriza mentioning HBO had rejected Murray and that it was Peterson.
I don't dislike Darni, I just think he's a little too confident for a man with little knowledge. Bar him insinuating I was a racist today, I've always found him really pleasant. I'm a big Beefheart fan, Trout Mask has good taste.